The problem of shaft effect has been the subject of magazine articles, see for example "Manners For The V-Max" in Motorcyclist, September 1987, pages 53-55. U.S. Pat. No. 4,336,859 to Leitner addresses the problem and suggests the use of an articulated arm in addition to the swing arm. In the Motorcyclist article, the author described shaft effect as "an unwanted by-product of any shaft-drive motorcycle's drive train set-up; simply put it's the tendency of the rear suspension to rise, sometimes violently, with the application of power to the rear wheel and fall, sometimes violently, under engine braking. Shaft effect happens because the swing arm and shaft housing of shaft drive bikes are called on to withstand massive amounts of torque when power is applied. The shaft housing is trying to rotate backward as the wheel is propelled forward, and the only thing that is stopping the shaft housing from spinning is its connection to the frame via the swing arm and drive-shaft tube. If there were no rear suspension, the load would be resolved in the frame . . . (but) because the rear wheel of a modern motorcycle is free to pivot up and down on the swing arm, controlled by the spring-damper unit or units, the torque effect at the shaft housing acts to extend the rear suspension, sometimes hard enough to top it out or make the rear suspension essentially rigid. Thus the rear suspension action of a drive-shaft machine . . . behaves one way with the throttle open and another with the throttle closed. If rear-wheel traction is lost for an instant, as it might be when hitting oil, sand or water while accelerating hard and cornering, the suspension can go through wild cycles of wheel hop, or at least vary greatly in stiffness, in the space of a couple of seconds."
The advantages of drive-shaft motorcycles are thus unfortunately accompanied by the major disadvantage of unpredictable suspension action, as a result of shaft effect.